Can't find i2s_std.h file anywhere

Question

I'm trying to use I2S with my esp32 NodeMCU, and I copied an example code provided by the espressif website. In the example code it includes a header file:

#include "driver/i2s_std.h"

But my IDE gives error when I include it, saying "fatal error: driver/i2s_std.h: No such file or directory"

I have already installed the I2S libraries and when I include for example:

#include "driver/i2s.h"

then it doesn't give error, but I can't include i2s_std.h file. I tried to find that header file online but I couldn't find it. Can somebody please help me?

Thanks a lot.